They have sythesized a dosage so potent that you can’t touch it IIRC. They call it black death. There is also some other type that is not quite as bad but worse than the normal kind. It’s name has a complicated chemical prefix I can no longer recall. Yay for the consequences of trying to get around a pointless drug war.

Edit: Carfentanyl is 100 times more potent that fentanyl. There is still one that even worse though.